Study on Acetylcellulose Sulfamic Acid, Ammonium Sulfamate, Hydroxylamine Sulfate as Catalyst of Acetylation

• Published in: Kobunshi Kagaku Vol. 26; no. 291; pp. 485 - 490
• Main Authors: Takahashi, Akira, Takahashi, Shiro
• Format: Journal Article
• Language: Japanese
• Published: The Society of Polymer Science, Japan 25.07.1969
• ISSN: 0023-2556; 1884-8079
• DOI: 10.1295/koron1944.26.485

Cotton linter is immersed in acetic acid aqueous solutions (1: 1 vol.) of sulfamic acid (SA), ammonium sulfamate (AS), hydroxylamine sulfate (HS). The excess imbibitionacid is removed by suction and then the cellulose is acetylated with a mixture of acetic anhydride and diluent at 50-100°C. Under appropriate conditions, cotton linter impregnated with the catalyst is acetylated smoothly; for example, triacetyl cellulose can be obtained in the acetylation by acetic anhydride at 70°C for 2-5 minutes. The catalytic effectiveness of these compounds is as follows;HS≥SA>AS The acetylation reaction is accelerated by the addition of the diluents which have only a little affinity to these catalysts, since the dissolution of the catalysts into the acetylating bath is prevented. Effectiveness of the catalysts and the diluents to obtain the acetate with high degree of polymerization is as follows;HS>SA=AS, CH2Cl2+C2H5OH>none>C6H6≥CH3COOH.